This invention relates to an electronic copy board system and a new electronic copy board for use therewith.
Recently, a new product has been introduced in the field of office appliances, and this product has been referred to as an Electronic Copy Board or ECB. The purposes of the ECB are to provide a large writing surface similar to a "blackboard" or a "presentation board" which can receive drawings, numbers, or other image data, and, generally, to convert the image data on the ECB to a reduced replica or hard copy sheet of paper. Generally, the ECB has a printer associated with it to provide the hard copies of the image data written on the ECB to participants at a meeting, for example. In general, the image data is written on the ECB with marking pencils, for example, to enable the written data on the ECB to be erased where feasible.
One prior art ECB utilizes a white opaque endless loop for the writing surface, with the endless loop being supported by a pair of rollers. A stationary, linear array of photodetectors is positioned on one side of the endless loop, and a source of light is also positioned on the same side of the loop to direct light at the image data on the writing surface. The image data reflected from the writing surface passes to the array of photodetectors to "read" this data. One of the rollers supporting the loop is driven to present the image data to the array of photodetectors for sequential reading of successive columns of image data. The length of the array of photodetectors is essentially the same as the height of the useful writing area of the ECB. A problem with this type of ECB is that it is difficult to get a sufficient amount of light onto the writing surface because the photodetectors have to be close to the surface of the writing area in order to read effectively.
A second variation in a prior art ECB relates to one which does not use an endless sheet of writing material but which uses a strip of opaque material which is supplied from a "feed roll". A "take-up roll" is used to pull the strip past the array of photodetectors to effect the reading of the image data as previously described. Generally, a first motor is required for the feed roll and a second motor is required for the take-up roll, thereby increasing the cost compared to the first variation mentioned in the previous paragraph. This second variation also suffers from the same reading difficulties mentioned with regard to the first variation.